The present research program is to increase our understanding of post-translational enzymatic methylation of free carboxyl groups in protein. The reaction is catalyzed by S-adenosylmethionine:protein-carboxyl O-methyltransferase (E.C.2.1.1.24, protein methylase II) with S-adenosyl-L-methionine as the methyl donor. The proposed work for the year will be: a) Enzymatic methyl esterification of pituitary poly peptide hormone to investigate the structure and function relationship of the hormone. b) Effect of enzymatic methylation on the erythrocyte glucose transporter activity. c) Structure requirements for the interaction between protein methylase II, S-adenosyl-L-methionine and methyl acceptor poly peptide.